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EDITOR'S NOlEBOOK Of tenons, planes and presidential desks by John Kelsey somehow never finds its way into print. For example, almost two years ago cabinetmaker Michael Lynch of San Francisco offered a hose-clamp compression joint he finds useful. Lynch turns the end of a spindle a couple of thousandths of an inch larger than the hole it will fit into. "Then the ends of the spindles are slightly reduced in diameter by slipping a worm clamp (used to tighten hoses onto fittings in car engines) over it and screwing the gear to compress the wood fibers. " He figures the tenon remains compressed until it takes on moisture from the glue in the mortise, then expands to its original size, locking the joint tightly together. Old-time chairmakers used a similar trick, by drying ten- C oned rungs and leaving mortised posts somewhat green. If the joint was tight at assembly, the rung would quickly take on moisture from the post and expand. Then the two would shrink together to equilibrium with the atmosphere. Lynch said that industry commonly squeezes round tenons of uniformly dry wood to get an interference fit, whence his idea. } knew that Bruce Hoadley at the University of Massachusetts had worked on industry's problem, so } sent Lynch's remarks to him for comment. Hoadley, direct as usual, bought a handful of hose clamps and began tightening them around tenons. Trouble was, they all broke before his instruments could measure any compression. He agrees that such a joint will work in principle, but doesn't think enough pressure can be generated by a 39' clamp. A further difficulty is the phenomenon of "compression set." Up to a point, deformed wood springs back when you add water. After that point, the fibers suffer permanent . damage and never return to their original size, which is why the handle of a hammer, left out in the rain, will swell tightly in the head, then become forever loose when the wood dries. The powerful industrial clamps are calibrated to avoid this. So we agreed to disagree: Hoadley can't measure any com- pression before the clamp breaks, yet Lynch's method works for Lynch. He adds, "} have been around long enough to know that the chairs hold up." Another tip about tenons came from correspondence earlier this year with a reader in upstate New York. Like many, he saws his tenons fat so they can be trimmed to fit their mortises. He'd found it difficult to get a square corner where the cheek and shoulder come together. His answer was to set the table saw a little deep when cutting the shoulder, leaving a shallow kerf in the cheek, as in the left drawing. The trouble with this trick is that it severs the wood fibers at the surface of the tenon cheek from the main body of wood. Yet those fibers, with glue, are what keep the tenon in the mortise. Nevertheless, I sent the letter along to Andy Marlow in York, Pa., to see what he could add, and got a surprise: "Make the clearance cut with the tenon surface instead 86 onducting a magazine that attempts to be a forum for its readers often produces interesting material that of against it. This method retains maximum gluing surface and is normal procedure in my shop. " The drawing is at right, the clearance cuts exaggerated for clarity. While President Carter was in Germany duringJuly, cabinetmaker Robert C. Whitley took his place in the Oval-Office. Whitley, of Bucks County, Pa. , who is conservator at Independence Hall and has reproduced many pieces of historic American furniture, was at the White House to measure, photograph and draw the President's desk. It's big-7 ft. by 5 ft.-and very ornate. It was made at Queen Victoria's order with English oak timbers salvaged from the HMS Resolute, which had been lost in the ice attempting to find the Northwest Passage. Victoria gave the desk to the American people in gratitude for the return of the wrecked ship. Several presidents used it, then it was consigned to basement storage, where Jacqueline Kennedy rediscovered it and brought it back to light. Now the Kennedy family wants an exact replica for the JFK library being built near Boston, and Whitley has the commission. When } wrote in Summer '78 about grinding the center of a gouge edge back of the corners, I thought I had a hot tip. Several readers, however, wrote to point out that the trick is thoroughly explained by Alexander Weygers in his book The Making of Tools (Van Nostrand Reinhold, 1973). Weygers sees the edge of the gouge as falling on the surface of -a cylinder when it is new, and on the surface of a cone when it is correctly ground. Robert Katz of San Diego, Calif. , adds that violin-makers always sharpen their gouges so that the outer edges cut the wood in advance of the center. "By sharpening this way it is possible to cut wood cleanly in any direction, even highly figured curly maple, " Katz says. A couple of generations ago, all manner of special-purpose planes were in production and readily available. But many of the old companies are long out of business. Survivors like Stanley have dropped most of their specialty tools to concentrate on industrial equipment and mass-market tools for the weekend handyman. Stanley says this is economic necessity, demand just isn't high enough. But now there is a new market among the growing numbers of serious amateur woodworkers. It is still small by Stanley's standards, but plenty big enough to support lavish mail-order tool catalogs and the small manufacturers who supply them. More than that, this new market has encour